Hydroponic culture of rhododendron

Soilless cultivation is characterized by replacing soil with man-made substrates. The soilless cultivation of rhododendron with solid substrate in Hunan Forestry Institute has achieved very satisfactory results. The variety is summer cuckoo, the crown structure of soilless cultivation is compact, the number of flowering is large, the flower diameter is large, and there are few diseases and insect pests. It not only improves the quality of flowers, but also greatly reduces the heavy physical work, so it is a cultivation method worth popularizing.

1. Preparation of matrix

The root system of rhododendron is very slender, which requires loose matrix to facilitate air permeability and drainage. 1 part of vermiculite, 1 part of pearl sand, 1 part of river sand and 1 part of cinder were mixed in proportion. After mixing the substrate, sterilize it with 0.1% carbendazim solution, mix it evenly into the substrate and cover the plastic film for 1 day. Then rinse with clean water for many times, dry, mix well with 0.4% agricultural compound fertilizer solution, then cover it with plastic film for a month, and then use it in the basin.

two。 Preparation of nutrient solution

Azaleas have strict requirements for fertilizers. During the growing period, thin fertilizer is applied diligently. According to the experiment, good results can be obtained by spraying low concentration foliar fertilizer with agricultural compound fertilizer as the main fertilizer, supplemented with trace elements, PH value controlled at about 5.

The preparation of a large number of elements: 1 liter of water plus 2 grams of agricultural compound fertilizer and 0.5 grams of magnesium sulfate is the standard solution.

The preparation of trace elements: 1 liter of water plus 20 grams of disodium ethylenediamine tetraacetate, 15 grams of ferrous sulfate, 4 grams of manganese sulfate, 6 grams of boric acid, 0.2 grams of zinc sulfate, 0.1 grams of copper sulfate and 0.2 grams of ammonium molybdate as mother liquor. When in use, 1 liter of standard liquid and 1 ml of trace element mother liquid are all elements.

The preparation of foliar fertilizer: 1 g urea, 1 g potassium dihydrogen phosphate, 0.02 g boric acid and 10.1 g V. B in 1 liter of water.

3. Water and fertilizer management

Because the substrate has good drainage and air permeability, but the water retention is poor, so the amount of water is generally more than that of soil culture, in order to keep the substrate moist; at this time, pregnant buds and leaf buds germinate, requiring a large amount of fertilizer, and the full amount of nutrient solution is poured once in about 10 days. From March until the buds burst, foliar fertilizer is sprayed every 15 days or so. After flowering, there is a large amount of water, in addition to watering every day, foliar watering should be carried out in the evening. At this time, the amount of fertilizer is also large, so it can be changed to irrigate the nutrient solution once a week and spray foliar fertilizer once a week to promote the sturdiness of new branches and facilitate flower bud differentiation. After the ambush, pay attention to keep the substrate moist, and sprinkle water to the leaf surface, the amount of fertilizer can be reduced to about 20 days to pour nutrient solution. After the autumn is cool, you can gradually increase the amount of fertilizer, apply a full amount of nutrient solution once in half a month, and spray 1 Mel foliar fertilizer twice to promote the robust growth of flower buds. After the beginning of winter, the physiological activity of rhododendron is weak, so it is not suitable to apply fertilizer, but can be watered properly according to the dry and wet degree of the substrate. In the process of cultivation, there were almost no diseases and insect pests.